#define GLFW_INCLUDE_VULKAN

#include <GLFW/glfw3.h>
#include <assert.h>
#include <math.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>

#define MIN(a, b) ((a) < (b) ? (a) : (b))
#define MAX(a, b) ((a) > (b) ? (a) : (b))
#define CLAMP(x, min, max) MAX((min), MIN(x, (max)))

#define NELEMS(arr) (sizeof(arr) / sizeof(arr[0]))

#define QUEUE_FAMILY_PROP_BUFFER_SIZE 16
#define EXT_PROP_BUFFER_SIZE 256
#define SURFACE_FMT_BUFFER_SIZE 64
#define PRESENT_MODE_BUFFER_SIZE 8
#define SWAPCHAIN_IMG_BUFFER_SIZE 4

#define MAX_SHADER_SIZE (8 * 1024)

typedef struct {
	float position[2], colour[3];
} vertex_t;

static const char *layers[] = { "VK_LAYER_KHRONOS_validation" };
static const char *extensions[] = {
	VK_KHR_SWAPCHAIN_EXTENSION_NAME,
};

static const char vert_shader_code[] = {
#embed VERT_SHADER_SPV
};

static const char frag_shader_code[] = {
#embed FRAG_SHADER_SPV
};

static const vertex_t vertices[] = {
	{ { 0.0, -0.5 }, { 1.0, 0.0, 0.0 } },
	{ { 0.5, 0.5 }, { 0.0, 1.0, 0.0 } },
	{ { -0.5, 0.5 }, { 0.0, 0.0, 1.0 } },
};

#define NEXTENSIONS NELEMS(extensions)

static void
key_callback(GLFWwindow *window, int key, int scancode, int action, int mods)
{
	(void)window;
	(void)scancode;
	(void)mods;

	switch (key) {
	case GLFW_KEY_Q:
		if (action == GLFW_PRESS)
			glfwSetWindowShouldClose(window, GL_TRUE);
		break;
	}
}

static VkShaderModule
load_shader_module(VkDevice dev, const char *code, size_t code_size)
{
	const VkShaderModuleCreateInfo create_info = {
		.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO,
		.codeSize = code_size,
		.pCode = (uint32_t *)code,
	};
	VkShaderModule mod;
	const VkResult result
	    = vkCreateShaderModule(dev, &create_info, nullptr, &mod);
	assert(result == VK_SUCCESS);

	return mod;
}

int main()
{
	// Set up window
	glfwInit();
	glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
	glfwWindowHint(GLFW_RESIZABLE, GLFW_FALSE);
	GLFWwindow *window = glfwCreateWindow(800, 600, "Foo", nullptr, nullptr);
	assert(window);

	// Register input callbacks
	glfwSetKeyCallback(window, key_callback);

	// Initialise Vulkan instance.
	const VkApplicationInfo app_info = {
		.sType = VK_STRUCTURE_TYPE_APPLICATION_INFO,
		.pApplicationName = "Foo",
		.applicationVersion = VK_MAKE_VERSION(1, 0, 0),
		.pEngineName = "No Engine",
		.engineVersion = VK_MAKE_VERSION(1, 0, 0),
		.apiVersion = VK_API_VERSION_1_0,
	};
	uint32_t glfw_ext_count = 0;
	const char **glfw_ext_names
	    = glfwGetRequiredInstanceExtensions(&glfw_ext_count);
	const VkInstanceCreateInfo inst_create_info = {
		.sType = VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO,
		.pApplicationInfo = &app_info,
		.enabledExtensionCount = glfw_ext_count,
		.ppEnabledExtensionNames = glfw_ext_names,
		.enabledLayerCount = sizeof(layers) / sizeof(layers[0]),
		.ppEnabledLayerNames = layers,
	};
	VkInstance inst;
	VkResult result = vkCreateInstance(&inst_create_info, nullptr, &inst);
	assert(result == VK_SUCCESS);

	// Create surface
	VkSurfaceKHR surface;
	result = glfwCreateWindowSurface(inst, window, nullptr, &surface);
	assert(result == VK_SUCCESS);

	// Select a physical device
	VkPhysicalDevice physical_dev;
	uint32_t dev_count = 1;
	result = vkEnumeratePhysicalDevices(inst, &dev_count, &physical_dev);
	assert(result == VK_SUCCESS || result == VK_INCOMPLETE);

	// Select queue family
	uint32_t queue_family_count = QUEUE_FAMILY_PROP_BUFFER_SIZE;
	VkQueueFamilyProperties
	    queue_family_props[QUEUE_FAMILY_PROP_BUFFER_SIZE];
	vkGetPhysicalDeviceQueueFamilyProperties(
	    physical_dev, &queue_family_count, queue_family_props);
	uint32_t queue_family;
	bool found_queue_family = false;
	for (unsigned i = 0; i < queue_family_count; ++i) {
		if (queue_family_props[i].queueFlags & VK_QUEUE_GRAPHICS_BIT) {
			VkBool32 surface_support = false;
			vkGetPhysicalDeviceSurfaceSupportKHR(
			    physical_dev, i, surface, &surface_support);
			if (surface_support) {
				found_queue_family = true;
				queue_family = i;
				break;
			}
		}
	}
	assert(found_queue_family);

	// Check that the physical device supports all extensions
	uint32_t ext_count = EXT_PROP_BUFFER_SIZE;
	VkExtensionProperties ext_props[EXT_PROP_BUFFER_SIZE];
	result = vkEnumerateDeviceExtensionProperties(
	    physical_dev, nullptr, &ext_count, ext_props);
	assert(result == VK_SUCCESS);
	bool supported[NEXTENSIONS] = {};
	for (unsigned i = 0; i < ext_count; ++i) {
		for (unsigned j = 0; j < NEXTENSIONS; ++j) {
			if (strcmp(extensions[j], ext_props[i].extensionName) == 0) {
				supported[j] = true;
				break;
			}
		}
	}
	for (unsigned j = 0; j < NEXTENSIONS; ++j) {
		if (!supported[j]) {
			fprintf(stderr, "Unsupported: %s\n", extensions[j]);
			assert(false);
		}
	}

	// Create the logical device and get the queue handle.
	float queue_priority = 1.0;
	const VkDeviceQueueCreateInfo queue_create_info = {
		.sType = VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO,
		.queueFamilyIndex = queue_family,
		.queueCount = 1,
		.pQueuePriorities = &queue_priority,
	};
	const VkDeviceCreateInfo dev_create_info = {
		.sType = VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO,
		.pQueueCreateInfos = &queue_create_info,
		.queueCreateInfoCount = 1,
		.enabledExtensionCount = NEXTENSIONS,
		.ppEnabledExtensionNames = extensions,
	};
	VkDevice dev;
	result = vkCreateDevice(physical_dev, &dev_create_info, nullptr, &dev);
	assert(result == VK_SUCCESS);
	VkQueue queue;
	vkGetDeviceQueue(dev, queue_family, 0, &queue);

	// Select a surface format, preferring R8G8B8A8_SRGB with
	// SRGB_NONLINEAR colour space.
	uint32_t surface_fmt_count = SURFACE_FMT_BUFFER_SIZE;
	VkSurfaceFormatKHR surface_fmts[SURFACE_FMT_BUFFER_SIZE];
	result = vkGetPhysicalDeviceSurfaceFormatsKHR(
	    physical_dev, surface, &surface_fmt_count, surface_fmts);
	assert(result == VK_SUCCESS);
	assert(surface_fmt_count > 0);
	VkSurfaceFormatKHR surface_fmt = surface_fmts[0];
	for (unsigned i = 0; i < surface_fmt_count; ++i) {
		if (surface_fmts[i].format == VK_FORMAT_R8G8B8A8_SRGB
		    && surface_fmts[i].colorSpace
		        == VK_COLOR_SPACE_SRGB_NONLINEAR_KHR) {
			surface_fmt = surface_fmts[i];
		}
	}

	// Query surface capabilities
	VkSurfaceCapabilitiesKHR surface_caps;
	result = vkGetPhysicalDeviceSurfaceCapabilitiesKHR(
	    physical_dev, surface, &surface_caps);
	assert(result == VK_SUCCESS);

	// Select swap chain extent
	VkExtent2D swapchain_extent;
	if (surface_caps.currentExtent.width == UINT32_MAX) {
		int width, height;
		glfwGetFramebufferSize(window, &width, &height);
		swapchain_extent.width = CLAMP(
		    (uint32_t)width, surface_caps.minImageExtent.width,
		    surface_caps.maxImageExtent.width);
		swapchain_extent.height = CLAMP(
		    (uint32_t)height, surface_caps.minImageExtent.height,
		    surface_caps.maxImageExtent.height);
	} else {
		swapchain_extent = surface_caps.currentExtent;
	}

	// Select image count
	uint32_t swapchain_img_count = surface_caps.minImageCount + 1;
	assert(
	    surface_caps.maxImageCount == 0
	    || swapchain_img_count <= surface_caps.maxImageCount);

	// Create the swap chain
	const VkSwapchainCreateInfoKHR swapchain_create_info = {
		.sType = VK_STRUCTURE_TYPE_SWAPCHAIN_CREATE_INFO_KHR,
		.surface = surface,
		.minImageCount = swapchain_img_count,
		.imageFormat = surface_fmt.format,
		.imageColorSpace = surface_fmt.colorSpace,
		.imageExtent = swapchain_extent,
		.imageArrayLayers = 1,
		.imageUsage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT,
		.imageSharingMode = VK_SHARING_MODE_EXCLUSIVE,
		.preTransform = surface_caps.currentTransform,
		.compositeAlpha = VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR,
		.presentMode = VK_PRESENT_MODE_FIFO_KHR,
		.clipped = VK_TRUE,
		.oldSwapchain = VK_NULL_HANDLE,
	};
	VkSwapchainKHR swapchain;
	result = vkCreateSwapchainKHR(
	    dev, &swapchain_create_info, nullptr, &swapchain);
	assert(result == VK_SUCCESS);

	// Retreive swapchain images
	VkImage swapchain_imgs[SWAPCHAIN_IMG_BUFFER_SIZE];
	swapchain_img_count = SWAPCHAIN_IMG_BUFFER_SIZE;
	result = vkGetSwapchainImagesKHR(
	    dev, swapchain, &swapchain_img_count, swapchain_imgs);
	assert(result == VK_SUCCESS);

	// Create swapchain image views
	VkImageView swapchain_img_views[SWAPCHAIN_IMG_BUFFER_SIZE];
	VkImageViewCreateInfo img_view_create_info = {
		.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO,
		.viewType = VK_IMAGE_VIEW_TYPE_2D,
		.format = surface_fmt.format,
		.components = {
			.r = VK_COMPONENT_SWIZZLE_IDENTITY,
			.g = VK_COMPONENT_SWIZZLE_IDENTITY,
			.b = VK_COMPONENT_SWIZZLE_IDENTITY,
			.a = VK_COMPONENT_SWIZZLE_IDENTITY,
		},
		.subresourceRange = {
			.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT,
			.baseMipLevel = 0,
			.levelCount = 1,
			.baseArrayLayer = 0,
			.layerCount = 1,
		},
	};
	for (unsigned i = 0; i < swapchain_img_count; ++i) {
		img_view_create_info.image = swapchain_imgs[i];
		result = vkCreateImageView(
		    dev, &img_view_create_info, nullptr, swapchain_img_views + i);
	}

	// Load vertex and fragment shader modules
	VkShaderModule vert_shader = load_shader_module(
	    dev, vert_shader_code, sizeof(vert_shader_code));
	VkShaderModule frag_shader = load_shader_module(
	    dev, frag_shader_code, sizeof(frag_shader_code));
	const VkPipelineShaderStageCreateInfo shader_stages[] = {
		[0] = {
			.sType = VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO,
			.stage = VK_SHADER_STAGE_VERTEX_BIT,
			.module = vert_shader,
			.pName = "main",
		},
		[1] = {
			.sType = VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO,
			.stage = VK_SHADER_STAGE_FRAGMENT_BIT,
			.module = frag_shader,
			.pName = "main",
		},
	};

	// Set up input configuration
	const VkVertexInputBindingDescription input_binding_descs[] = {
		{
		    .binding = 0,
		    .stride = sizeof(vertex_t),
		    .inputRate = VK_VERTEX_INPUT_RATE_VERTEX,
		},
	};
	const VkVertexInputAttributeDescription input_attribute_descs[] = {
		{
		    .binding = 0,
		    .location = 0,
		    .format = VK_FORMAT_R32G32_SFLOAT,
		    .offset = offsetof(vertex_t, position),
		},
		{
		    .binding = 0,
		    .location = 1,
		    .format = VK_FORMAT_R32G32B32_SFLOAT,
		    .offset = offsetof(vertex_t, colour),
		},
	};
	const VkPipelineVertexInputStateCreateInfo vertex_input_config = {
		.sType = VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_STATE_CREATE_INFO,
		.vertexBindingDescriptionCount = NELEMS(input_binding_descs),
		.pVertexBindingDescriptions = input_binding_descs,
		.vertexAttributeDescriptionCount = NELEMS(input_attribute_descs),
		.pVertexAttributeDescriptions = input_attribute_descs,
	};
	const VkPipelineInputAssemblyStateCreateInfo input_assembly_config = {
		.sType = VK_STRUCTURE_TYPE_PIPELINE_INPUT_ASSEMBLY_STATE_CREATE_INFO,
		.topology = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP,
	};

	// Set up viewport configuration
	const VkViewport viewport = {
		.width = (float)swapchain_extent.width,
		.height = (float)swapchain_extent.height,
	};
	const VkRect2D scissor = { .extent = swapchain_extent };
	VkPipelineViewportStateCreateInfo viewport_config = {
		.sType = VK_STRUCTURE_TYPE_PIPELINE_VIEWPORT_STATE_CREATE_INFO,
		.viewportCount = 1,
		.pViewports = &viewport,
		.scissorCount = 1,
		.pScissors = &scissor,
	};

	// Populate rasterizer configuration
	const VkPipelineRasterizationStateCreateInfo rasterizer_config = {
		.sType = VK_STRUCTURE_TYPE_PIPELINE_RASTERIZATION_STATE_CREATE_INFO,
		.depthClampEnable = VK_FALSE,
		.rasterizerDiscardEnable = VK_FALSE,
		.polygonMode = VK_POLYGON_MODE_FILL,
		.lineWidth = 1.0f,
		.cullMode = VK_CULL_MODE_NONE,
	};

	// Populate multisampling configuration
	const VkPipelineMultisampleStateCreateInfo multisampling_config = {
		.sType = VK_STRUCTURE_TYPE_PIPELINE_MULTISAMPLE_STATE_CREATE_INFO,
		.sampleShadingEnable = VK_FALSE,
		.rasterizationSamples = VK_SAMPLE_COUNT_1_BIT,
	};

	// Set up colour blending configuration
	const VkPipelineColorBlendAttachmentState colour_blend_attatchment = {
		.colorWriteMask = VK_COLOR_COMPONENT_R_BIT | VK_COLOR_COMPONENT_G_BIT
		    | VK_COLOR_COMPONENT_B_BIT | VK_COLOR_COMPONENT_A_BIT,
		.blendEnable = VK_FALSE,
	};
	const VkPipelineColorBlendStateCreateInfo colour_blend_config = {
		.sType = VK_STRUCTURE_TYPE_PIPELINE_COLOR_BLEND_STATE_CREATE_INFO,
		.logicOpEnable = VK_FALSE,
		.attachmentCount = 1,
		.pAttachments = &colour_blend_attatchment,
	};

	// Create pipeline layout
	const VkPipelineLayoutCreateInfo pipeline_layout_config = {
		.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO,
		.pushConstantRangeCount = 0,
	};
	VkPipelineLayout pipeline_layout;
	result = vkCreatePipelineLayout(
	    dev, &pipeline_layout_config, nullptr, &pipeline_layout);
	assert(result == VK_SUCCESS);

	// Set up colour attachment
	const VkAttachmentDescription colour_attachment = {
		.format = surface_fmt.format,
		.samples = VK_SAMPLE_COUNT_1_BIT,
		.loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR,
		.storeOp = VK_ATTACHMENT_STORE_OP_STORE,
		.stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE,
		.stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE,
		.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED,
		.finalLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR,
	};
	const VkAttachmentReference colour_attachment_ref = {
		.attachment = 0,
		.layout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL,
	};
	const VkSubpassDescription subpass = {
		.pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS,
		.colorAttachmentCount = 1,
		.pColorAttachments = &colour_attachment_ref,
	};

	// Create render pass
	const VkSubpassDependency dependency = {
		.srcSubpass = VK_SUBPASS_EXTERNAL,
		.dstSubpass = 0,
		.srcStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT,
		.srcAccessMask = 0,
		.dstStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT,
		.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT,
	};
	const VkRenderPassCreateInfo render_pass_config = {
		.sType = VK_STRUCTURE_TYPE_RENDER_PASS_CREATE_INFO,
		.attachmentCount = 1,
		.pAttachments = &colour_attachment,
		.subpassCount = 1,
		.pSubpasses = &subpass,
		.dependencyCount = 1,
		.pDependencies = &dependency,
	};
	VkRenderPass render_pass;
	result = vkCreateRenderPass(
	    dev, &render_pass_config, nullptr, &render_pass);
	assert(result == VK_SUCCESS);

	// Create pipeline
	const VkGraphicsPipelineCreateInfo pipeline_config = {
		.sType = VK_STRUCTURE_TYPE_GRAPHICS_PIPELINE_CREATE_INFO,
		.stageCount = 2,
		.pStages = shader_stages,
		.pVertexInputState = &vertex_input_config,
		.pInputAssemblyState = &input_assembly_config,
		.pViewportState = &viewport_config,
		.pRasterizationState = &rasterizer_config,
		.pMultisampleState = &multisampling_config,
		.pColorBlendState = &colour_blend_config,
		.layout = pipeline_layout,
		.renderPass = render_pass,
		.subpass = 0,
	};
	VkPipeline pipeline;
	result = vkCreateGraphicsPipelines(
	    dev, VK_NULL_HANDLE, 1, &pipeline_config, nullptr, &pipeline);
	assert(result == VK_SUCCESS);

	// Create framebuffers
	VkFramebuffer framebuffers[SWAPCHAIN_IMG_BUFFER_SIZE];
	for (unsigned i = 0; i < swapchain_img_count; ++i) {
		const VkFramebufferCreateInfo framebuffer_config = {
			.sType = VK_STRUCTURE_TYPE_FRAMEBUFFER_CREATE_INFO,
			.renderPass = render_pass,
			.attachmentCount = 1,
			.pAttachments = swapchain_img_views + i,
			.width = swapchain_extent.width,
			.height = swapchain_extent.height,
			.layers = 1,
		};
		result = vkCreateFramebuffer(
		    dev, &framebuffer_config, nullptr, framebuffers + i);
		assert(result == VK_SUCCESS);
	}

	// Create vertex buffer
	const VkBufferCreateInfo vertex_buffer_config = {
		.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO,
		.size = sizeof(vertices),
		.usage = VK_BUFFER_USAGE_VERTEX_BUFFER_BIT,
		.sharingMode = VK_SHARING_MODE_EXCLUSIVE,
	};
	VkBuffer vertex_buffer;
	result = vkCreateBuffer(
	    dev, &vertex_buffer_config, nullptr, &vertex_buffer);
	assert(result == VK_SUCCESS);

	// Allocate memory to vertex buffer
	const VkMemoryPropertyFlags mem_flags
	    = VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT
	    | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT;
	VkMemoryRequirements mem_requirements;
	vkGetBufferMemoryRequirements(dev, vertex_buffer, &mem_requirements);
	VkPhysicalDeviceMemoryProperties mem_props;
	vkGetPhysicalDeviceMemoryProperties(physical_dev, &mem_props);
	uint32_t mem_type = UINT32_MAX;
	for (unsigned i = 0; i < mem_props.memoryTypeCount; ++i) {
		const bool valid_type
		    = (mem_requirements.memoryTypeBits & (1 << i)) != 0;
		const bool has_flags
		    = (mem_props.memoryTypes[i].propertyFlags & mem_flags)
		    == mem_flags;
		if (valid_type && has_flags) {
			mem_type = i;
			break;
		}
	}
	assert(mem_type != UINT32_MAX);
	VkMemoryAllocateInfo allocate_config = {
		.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO,
		.allocationSize = mem_requirements.size,
		.memoryTypeIndex = mem_type,
	};
	VkDeviceMemory vertex_buffer_mem;
	result = vkAllocateMemory(
	    dev, &allocate_config, nullptr, &vertex_buffer_mem);
	assert(result == VK_SUCCESS);
	vkBindBufferMemory(dev, vertex_buffer, vertex_buffer_mem, 0);

	// Copy vertex data into vertex buffer
	void *vertex_data;
	vkMapMemory(
	    dev, vertex_buffer_mem, 0, sizeof(vertices), 0, &vertex_data);
	memcpy(vertex_data, vertices, sizeof(vertices));
	vkUnmapMemory(dev, vertex_buffer_mem);

	// Create command pool
	const VkCommandPoolCreateInfo cmd_pool_config = {
		.sType = VK_STRUCTURE_TYPE_COMMAND_POOL_CREATE_INFO,
		.flags = VK_COMMAND_POOL_CREATE_RESET_COMMAND_BUFFER_BIT,
		.queueFamilyIndex = queue_family,
	};
	VkCommandPool cmd_pool;
	result = vkCreateCommandPool(dev, &cmd_pool_config, nullptr, &cmd_pool);
	assert(result == VK_SUCCESS);

	// Allocate command buffer
	const VkCommandBufferAllocateInfo cmd_buf_config = {
		.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO,
		.commandPool = cmd_pool,
		.level = VK_COMMAND_BUFFER_LEVEL_PRIMARY,
		.commandBufferCount = 1,
	};
	VkCommandBuffer cmd_buf;
	result = vkAllocateCommandBuffers(dev, &cmd_buf_config, &cmd_buf);
	assert(result == VK_SUCCESS);

	// Create syncronisation primitives
	VkSemaphore img_avail, render_fin;
	VkSemaphoreCreateInfo semaphore_config
	    = { .sType = VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO };
	result = vkCreateSemaphore(dev, &semaphore_config, nullptr, &img_avail);
	assert(result == VK_SUCCESS);
	result = vkCreateSemaphore(dev, &semaphore_config, nullptr, &render_fin);
	assert(result == VK_SUCCESS);
	VkFence in_flight;
	VkFenceCreateInfo fence_config = {
		.sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO,
		.flags = VK_FENCE_CREATE_SIGNALED_BIT,
	};
	result = vkCreateFence(dev, &fence_config, nullptr, &in_flight);
	assert(result == VK_SUCCESS);

	while (!glfwWindowShouldClose(window)) {
		glfwPollEvents();

		// Wait for previous frame to finish
		vkWaitForFences(dev, 1, &in_flight, VK_TRUE, UINT64_MAX);
		vkResetFences(dev, 1, &in_flight);

		// Aquire image from swapchain
		uint32_t img_index;
		result = vkAcquireNextImageKHR(
		    dev, swapchain, UINT64_MAX, img_avail, VK_NULL_HANDLE,
		    &img_index);
		assert(result == VK_SUCCESS);

		// Reset command buffer, then begin writing
		vkResetCommandBuffer(cmd_buf, 0);
		const VkCommandBufferBeginInfo cmd_begin = {
			.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO,
		};
		result = vkBeginCommandBuffer(cmd_buf, &cmd_begin);
		assert(result == VK_SUCCESS);

		// Start render pass
		VkClearValue clear_value = { { { 0.0, 0.0, 0.0, 1.0 } } };
		VkRenderPassBeginInfo render_pass_begin = {
			.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO,
			.renderPass = render_pass,
			.framebuffer = framebuffers[img_index],
			.renderArea.extent = swapchain_extent,
			.clearValueCount = 1,
			.pClearValues = &clear_value,
		};
		vkCmdBeginRenderPass(
		    cmd_buf, &render_pass_begin, VK_SUBPASS_CONTENTS_INLINE);

		// Bind graphics pipeline and vertex buffer, then draw
		vkCmdBindPipeline(
		    cmd_buf, VK_PIPELINE_BIND_POINT_GRAPHICS, pipeline);
		vkCmdBindVertexBuffers(
		    cmd_buf, 0, 1, &vertex_buffer, &(VkDeviceSize) { 0 });
		vkCmdDraw(cmd_buf, NELEMS(vertices), 1, 0, 0);

		// Finish render pass and end writing to command buffer
		vkCmdEndRenderPass(cmd_buf);
		result = vkEndCommandBuffer(cmd_buf);
		assert(result == VK_SUCCESS);

		// Submit command buffer
		VkPipelineStageFlags wait_stage
		    = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
		const VkSubmitInfo submit = {
			.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO,
			.waitSemaphoreCount = 1,
			.pWaitSemaphores = &img_avail,
			.pWaitDstStageMask = &wait_stage,
			.commandBufferCount = 1,
			.pCommandBuffers = &cmd_buf,
			.signalSemaphoreCount = 1,
			.pSignalSemaphores = &render_fin,
		};
		result = vkQueueSubmit(queue, 1, &submit, in_flight);
		assert(result == VK_SUCCESS);

		// Present frame
		const VkPresentInfoKHR present_info = {
			.sType = VK_STRUCTURE_TYPE_PRESENT_INFO_KHR,
			.waitSemaphoreCount = 1,
			.pWaitSemaphores = &render_fin,
			.swapchainCount = 1,
			.pSwapchains = &swapchain,
			.pImageIndices = &img_index,
		};
		result = vkQueuePresentKHR(queue, &present_info);
		assert(result == VK_SUCCESS);
	}

	vkDeviceWaitIdle(dev);

	// Clean up
	vkDestroySemaphore(dev, img_avail, nullptr);
	vkDestroySemaphore(dev, render_fin, nullptr);
	vkDestroyFence(dev, in_flight, nullptr);
	vkDestroyCommandPool(dev, cmd_pool, nullptr);
	vkDestroyPipeline(dev, pipeline, nullptr);
	vkDestroyRenderPass(dev, render_pass, nullptr);
	vkDestroyPipelineLayout(dev, pipeline_layout, nullptr);
	vkDestroyShaderModule(dev, vert_shader, nullptr);
	vkDestroyShaderModule(dev, frag_shader, nullptr);
	for (unsigned i = 0; i < swapchain_img_count; ++i) {
		vkDestroyFramebuffer(dev, framebuffers[i], nullptr);
		vkDestroyImageView(dev, swapchain_img_views[i], nullptr);
	}
	vkDestroySwapchainKHR(dev, swapchain, nullptr);
	vkDestroyBuffer(dev, vertex_buffer, nullptr);
	vkFreeMemory(dev, vertex_buffer_mem, nullptr);
	vkDestroyDevice(dev, nullptr);
	vkDestroySurfaceKHR(inst, surface, nullptr);
	vkDestroyInstance(inst, nullptr);
	glfwDestroyWindow(window);
	glfwTerminate();
}